This invention relates generally to radiation imaging systems and in particular to x-ray radiography imaging systems.
Imaging arrays typically include a photosensor array coupled to a scintillating medium. Radiation absorbed in the scintillator generates optical photons which in turn pass into a photosensor, such as a photodiode. To increase resolution, some known imaging systems utilize a dynamic focal spot wobble technique which increases a computed tomography imaging system resolution by manipulating the position of an x-ray focal spot during data acquisition. Other known imaging systems increase a resolving power of the imaging system by combining projection data that are scanned 180 degrees apart. At least one known imaging array includes a photodiode panel with a pitch size of approximately 100 microns that can only achieve a resolution as high as 5 lp/mm (line pairs per millimeter) from a single measurement due to limits set by the sampling rate and the corresponding Nyquist frequency. For example, in signal processing, an ideal detector with an aperture size of d has a frequency resolving power up to 1/d in a Fourier domain before its Modulation Transfer Function (MTF) curve of a SINC function hits its first zero node. At least one known linear array detector with a pitch size of d can only resolve a spatial frequency up to the Nyquist frequency 1/2 d, if only one measurement is taken.